Carburetor for internal combustion engines

ABSTRACT

A carburetor for internal combustion engines in which a radial outlet arm for fuel or fuel and equalization air terminates in the central bore of a ring-shaped pre-atomizer which projects into the diffusor, at least one approximately radial air channel thereby terminates in the central bore while the discharge opening of this air channel is disposed between the outlet arm and the atomizer discharge into the diffusor.

United States Patent [191 Blohm 1451 May 14, 1974 CARBURETOR FOR INTERNAL 1,275,032 8/1918 Huene.... 261/78 R COMBUSTION ENGINES 3,648,988 3/1972 Dibert 26l/DIG. 39

[75] Inventor: Hans-Jochen Blohm, Neustadt, FOREIGN PATENTS OR APPLICATIONS Germany 720,533 5/1942 Germany 261/78 R 829,677 1 1952 G 261 78 R [731 Assignee: Daimler'Benz Akfiengfseuschafi 602,404 3i1926 26l/Dl 39 stuttgart-Umerturkhelm, Germany 881,461 11/1961 Great Britain 261/78 R [22] Filed: Nov. 4, 1971 Primary ExaminerT1m R. Miles [21 1 Appl- N05 195,672 Attorney, Agent, or Firm-Craig and A nton elli [30] Foreign Application Priority Data ABSTRACT Nov. 5, 1970 Germany 2054430 A carburetor for internal combustion engines in which a'radial outlet arm for fuel or fuel and equalization air [52] U.S. Cl. 261/78 R, 261/DlG. 39 terminates in the central bore of a ring-shaped pre- [51] Int. Cl. F02m 19/08 atomizer which projects into the diffuser, at least one [58] Field of Search 261/78 R, DIG. 39 approximately radial air channel thereby terminates in the central bore while the discharge opening of this air [56] References Cited channel is disposed between the outlet arm and the UNITED STATES PATENTS atomizer discharge into the diffuser.

3,295,839 1 1967 Mitchell 261 41 D 6 Claims, 2 Drawing Figures CARBURETOR FOR INTERNAL COMBUSTION ENGINES The present invention relates to a carburetor for internal combustion engines, in which a radial discharge arm for fuel or fuel and equalization air terminates in the central bore of a ring-shaped pre-atomizer projecting coaxially into the diffusor.

As a consequence of measures carried out by reason of official exhaust regulations for leaning the suction mixture, with the use of carburetors of the aforementioned type, so-called jerking or bucking appearances occur during the operation and more particularly dur ing the drive of the vehicle. The present invention is concerned with the task to eliminate these bucking appearances. The underlying problems are solved according to the present invention in that at least one essentially radial air channel terminates in the central bore and the air channel discharge aperture is disposed between the discharge arm and the atomizer discharge into the diffusor. The air flow of the air channel according to the present invention impinges on the fuel-airmixture leaving the discharge arm and effects a particularly fine, thorough atomization which supplies a uniform and continuous composition of the mixture. The suspected causes-as for example non-uniform discharge of the mixture out of the pre-atomizer-for the disturbing bucking appearances are eliminated thereby and an improved atomization is achieved already at small partial loads so that the leaning of the mixture can be still further increased.

For achieving a high flow energy in the air channel, the latter might be in communication with the atmosphere-possibly by the interconnection of a nozzle. However, tests have demonstrated that the pressure difference between the pressure at the atomizer discharge into the diffusor and the pressure in the carburetor chamber connected upstream of the diffusor in the direction of flow is adequate for the indicated purpose. Consequently, provision is made in one embodiment of the carburetor according to the present invention that the air channel is in communication with the carburetor chamber surrounding the pre-atomizer and disposed between diffusor and the air inlet connection.

In order to permit the air-flow according to the present invention to impinge as early as possible on the mixture particles after leaving the discharge arm, according to a further feature of the present invention it is additionally proposed that the air channel discharge be located in proximity to the discharge aperture of the discharge arm.

Accordingly, it is an object of the present invention to provide a carburetor for internal combustion engines which avoids by simple means the aforementioned shortcomings and drawbacks encountered in the prior art.

Another object of the present invention resides in a carburetor for internal combustion engines in which the so-called bucking or chucking appearances are farreachingly eliminated when leaning down the suction Still another object of the present invention resides in a carburetor for internal combustion engines which permits a further leaning of the suction mixture without impairing the proper operation of the engine.

These and further objects, features and advantages of the present invention will become more apparent from the following description when taken in connection with the accompanying drawing which shows, for purposes of illustration only, one embodiment in accordance with the present invention, and wherein:

FIG. 1 is an axial cross sectional view through a carburetor illustrating exclusively those parts essential for the present invention such as pre-atomizer and diffusor, and

FIG. 2 is a cross sectional view taken along line ll-ll of FIG. 1.

Referring now to the drawing wherein like reference numerals are used throughout the two views to designate like parts, the ring-shaped pre-atomizer 10 is inserted into the otherwise conventional carburetor housing, not illustrated in detail, by means of two radial securing arms 11 and 12 in such a manner that the wide atomizer discharge opening 13 protrudes into the diffusor l4 and the narrow atomizer inlet aperture 16 disposed at the opposite end of the central bore 15 is located in the intermediate chamber 17 disposed between air diffusor 14 and the air inlet pipe connection (not shown).

A tubularly shaped outlet or discharge arm l8extends through the securing arm 12, whose bore 19 serves for the supply of fuel to the pre-atomizer l0 during the starting operation or of a mixture of fuel and equalization air during load operation. The discharge orifice 20 of the bore 19 lies near the atomizer inlet aperture l6.

Directly downstream of the discharge aperture 20 a slot 22 is provided in the wall 21 of the pre-atomizer 10 so that an air channel 23 is formed which connects the intermediate chamber 17 with the central bore 15. The longitudinal axis of the air channel 23 is disposed essen tially radially to the axis 24 of the pre-atomizer l0 arranged coaxially to the diffusor 14. The orifice 25 of the air channel 23 is located closely below the orifice 20, out of which flows the mixture so that the air-flow impinges on the mixture directly after leaving the bore 19. A particularly fine atomization is achieved thereby also at small partial loads.

While I have shown and described only one embodiment in accordance with the present invention, it is understood that the same is not limited thereto but is susceptible of numerous changes and modifications as known to those skilled in the art and I therefore do not wish to be limited to the details shown and described herein but intend to cover all such changes and modifications as are encompassed by the scope of the appended claims.

What I claim is:

l. A carburetor for an internal combustion engine, comprising: i

a carburetor housing, a diffusor means disposed in said housing, a preatomizing nozzle means discharging into said diffusor means, said preatomiz-' ing nozzle means including a central bore, the

cross-sectional area of which first decreases and then increases from the intake portion thereof to the discharge portion thereof,

a radially directed fuel nozzle means for supplying a fuel mixture terminating in a wall of said central bore below the point of minimum cross-sectional area, and by-pass air channel means for supplying an air flow directly on said fuel mixture supplied by said fuel nozzle means,

said by-pass air channel means consisting of a single opening connected to a wall of said central bore, said single opening being disposed directly downstream of and in the same radial sector of said wall as said fuel nozzle means.

2. A carburetor according to claim 1, further comprising an air inlet connection, and a carburetor chamber surrounding said pre-atomizer means disposed between said diffusor means and said air inlet connection, said air channel means being in communication with said carburetor chamber.

3. A carburetor according to claim 1, wherein said air channel means is terminated in said central bore in close proximity to the discharge of said fuel nozzle means.

4. A carburetor according to claim 1, wherein said preatomizer means is substantially annularly shaped and projects coaxially into said diffusor means.

5. A carburetor according to claim 4, further comprising an air inlet connection, and a carburetor chamber surrounding said pre-atomizer means disposed between said diffusor means and said air inlet connection, said air channel means being in communication with said carburetor chamber.

6. A carburetor according to claim 5, wherein said air channel means is terminated in said central bore in close proximity to the discharge of said fuel nozzle 

1. A carburetor for an internal combustion engine, comprising: a carburetor housing, a diffusor means disposed in said housing, a preatomizing nozzle means discharging into said diffusor means, said preatomizing nozzle means including a central bore, the cross-sectional area of which first decreases and then increases from the intake portion thereof to the discharge portion thereof, a radially directed fuel nozzle means for supplying a fuel mixture terminating in a wall of said central bore below the point of minimum cross-sectional area, and by-pass air channel means for supplying an air flow directly on said fuel mixture supplied by said fuel nozzle means, said by-pass air channel means consisting of a single opening connected to a wall of said central bore, said single opening being disposed directly downstream of and in the same radial sector of said wall as said fuel nozzle means.
 2. A carburetor according to claim 1, further compRising an air inlet connection, and a carburetor chamber surrounding said pre-atomizer means disposed between said diffusor means and said air inlet connection, said air channel means being in communication with said carburetor chamber.
 3. A carburetor according to claim 1, wherein said air channel means is terminated in said central bore in close proximity to the discharge of said fuel nozzle means.
 4. A carburetor according to claim 1, wherein said preatomizer means is substantially annularly shaped and projects coaxially into said diffusor means.
 5. A carburetor according to claim 4, further comprising an air inlet connection, and a carburetor chamber surrounding said pre-atomizer means disposed between said diffusor means and said air inlet connection, said air channel means being in communication with said carburetor chamber.
 6. A carburetor according to claim 5, wherein said air channel means is terminated in said central bore in close proximity to the discharge of said fuel nozzle means. 